Outside an abortion clinic in Toledo, Ohio, the protesters gather silently. They clutch crucifixes. Some kneel in the road.

Inside it is quiet, calm and the facilities are pretty basic. Because of the protesters, most mainstream hospitals have stopped providing abortions, gynaecologist Dr Martin Ruddock tells me. Here they serve many women from low-income neighbourhoods.

Because of threats to his life by pro-life campaigners, Dr Ruddock travels to work in a bullet-proof vest.

Now Ohio is on the front line of America's abortion furore, which has been cranked up massively during the Republican Party's primary season. While presidential candidates have vied with each other to sound more anti-abortion, the past 12 months have seen a major attempt to tighten abortion laws at state level.

When Virginia tried to introduce a similar law, there was uproar; numerous states already ban abortion after 20 weeks. In Oklahoma, a bill to give a foetus "personhood" from the moment of conception creates an implicit challenge to the existing legal settlement that has yet to be tested in the courts.

They are doing it to drive doctors away, to make the procedure more expensive, to make it more costly to scare women awayMartin Ruddock, Doctor

In Ohio, anti-abortion campaigners are pushing for a so-called "heartbeat bill" - which would define a foetus as alive once a heartbeat is detected and effectively limit legal abortion to around six weeks.

Anita Rios, who has campaigned for abortion access since before the historic Roe v Wade decision made abortion legal in 1973, and who works at the Toledo Clinic, told me the impact of the political furore, and the state level restrictions, is already tangible:

"The strategy is to put these laws into place state by state and erode and destroy access to abortions and that is what's working."

Workers at the clinic told me of women turning up already convinced that the proposed law - which would most likely be deemed unconstitutional - was in force.

The law requiring them to make two visits to the clinic meant, for some of the poorest, long hours of travel and hardship. On entry to the clinic, some are handed small rubber models of foetuses by the protesters.

The combined effect of the rhetoric, the protests and the legal changes at state level, says Ms Rios, "makes it harder to fund and use these services. And it creates a burden of guilt and shame".

And she says, while middle class women will always be able to get an abortion; the restrictions on provision are hitting the poorest hardest.

In the small town of Findlay, Ohio, they see things differently. Here I met some of those campaigning for the Heartbeat Bill: Republican voters from the religious right, they believe America's abortion law to be creating "a holocaust".

Barb McKinch, one of the Heartbeat Bill activists told me they were fully prepared to see the Republicans lose votes on the issue:

"The time has come regardless if our candidate wins or loses. The time has come to stand up for what's right."

"America needs to wake up: it is genocide," another campaigner, Rachelle Heidelbaugh, told me. "You couldn't really have a political candidate who denied that, it would be like having a holocaust denier," I asked her. "Exactly," she replied.

The campaigners told me the aim with the Heartbeat Bill - here and in other states - is to create momentum for a decisive challenge in the Supreme Court that would overturn Roe vs Wade.

Image copyrightAPImage caption
A number of anti-abortion measures have been voted on and some have been implemented at state level

The debate is being conducted in language that is shocking and extreme. And while it has fired up a new generation of feminist activists, who see it as a "war over women's bodies", its biggest impact may be among those normally conservative women voters who cannot accept the hard line on abortion.

Among women, Republican frontrunner Mitt Romney is now polling up to 18 points behind President Barack Obama in battleground states.

The tipping point came when the Obama administration introduced contraception into its new healthcare system: all the Republican presidential candidates responded in the language of apoplexy. Mitt Romney, who as governor of Massachusetts had not rushed to repeal a similar provision, declared Obama's new law "an attack on religious freedom".

Mitch Daniels, governor of Indiana and once tipped for the presidential race himself, called last year for the party to engage in a "social truce". Now he is despondent over the way reproductive rights issues are skewing the campaign.

"[The Republican candidates] haven't handled this very well, but they didn't bring this issue up the president did. I'm not a conspiracy theorist but if this was a gambit on the part of the administration, it worked beautifully. Some of our people took the bait."

He believes the party's focus on social issues could doom its prospects in November:

"At this stage our party could be doing a lot better. I like to say that given the failure of his policies, a weak economy and high energy prices, it would be very hard to lose an election to President Obama. But we've just the team to do it."

Outside the Toledo clinic the vigil continues into the evening. Inside, Dr Ruddock vents his exasperation at the intrusion by lawmakers into what he believes should be matters of medical practice.

He shows me the normal ultrasound device, which is used to scan a woman's uterus from outside the body. Then he demonstrates the "transvaginal" probe - a long plastic device which is used only where complications make the normal sensor impossible:

"To mandate the use of this would be an absolute intrusion into women's reproductive healthcare and it is totally unnecessary in the practice of abortion practice," he says.

Anita Rios puts it more bluntly. Like many pro-choice campaigners, she believes it is "state-sponsored rape".

Dr Ruddock says: "They are doing it to drive doctors away, to make the procedure more expensive, to make it more costly to scare women away, basically to put additional obstacles one after the other in the path of a woman who is pregnant, and doesn't want to be, to try and get access to a compassionate abortion provider."

In some ways, this argument is a part of the wider culture war between liberals and conservatives in America. It is certainly fuelling the conflict between conservative-run states and the federal government that will define any second-term Obama administration.

What is new are the results at local level. Almost silently, legal abortion for women from the poorest neighbourhoods of America has become harder and harder.